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Cryogenic and conventional milling of AZ91 magnesium alloy

Journal of magnesium and Alloys 2024年第6期12卷 2503-2519页

作者： Vikas marakini Srinivasa pai p Gururaj Bolar Bhaskara p Achar Department of mechanical Engineering Nitte(Deemed to be University)NMAM Institute of Technology(NMAMIT)Nitte 574110India Department of mechanical and Industrial Engineering Manipal Institute of TechnologyManipal Academy of Higher EducationManipal 576104India

Use of magnesium is the need of the hour due to its low density as well as its high strength-to-weight and stiffness-to-weight ratio *** study focuses on the effectiveness of liquid nitrogen(LN_(2))assisted cryogenic machining on the surface integrity(SI)characteristics of AZ91 magnesium *** milling using uncoated carbide inserts have been performed under liquid nitrogen(LN_(2))assisted cryogenic condition and compared with conventional(dry)*** are performed using machining parameters in terms of cutting speeds of 325,475,625 m/min,feed rates of 0.05,0.1,0.15 mm/teeth and depth of cuts of 0.5,1,1.5 mm *** significant surface integrity characteristics such as surface roughness,microhardness,microstructure,and residual stresses have been *** of SI characteristics with respect to milling parameters have been identified using statistical technique such as ANOVA and signal-to-noise(S/N)ratio ***,the multi criteria decision making(mCDm)techniques such as additive ratio assessment method(ARAS)and complex proportional assessment(COpRAS)have been utilized to identify the optimal conditions for milling AZ91 magnesium alloy under both dry and cryogenic *** of LN_(2)during machining,resulted in reduction in machining temperature by upto 29%with a temperature drop from 251.2℃under dry condition to 178.5℃in cryogenic *** showed the advantage of performing cryogenic milling in improving the surface integrity to a significant *** machining considerably minimized the roughness by upto 28%and maximised the microhardness by upto 23%,when compared to dry *** speed has caused significant impact on surface roughness(95.33%-dry,92.92%-cryogenic)and surface microhardness(80.33%-dry,82.15%-cryogenic).Due to the reduction in machining temperature,cryogenic condition resulted in compressive residual stresses(maximumσ║=-113 mpa)on the alloy *** indicate no

关键词： magnesium alloy Cryogenic machining Roughness microhardness microstructure Residual stress multi criteria decision making

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Comparative analysis of microstructure,mechanical,and corrosion properties of biodegradable mg-3Y alloy prepared by selective laser melting and spark plasma sintering

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Journal of magnesium and Alloys 2024年第4期12卷 1496-1510页

作者： p.minárik m.Zemková S.Šašek J.Dittrich m.Knapek F.Lukáˇc D.Koutný J.Jaroš R.Král Faculty of mathematics and physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic Research Centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of plasma physics of the Czech Academy of Sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of machine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of biodegradable magnesium alloy mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(SpS)and selective laser melting(SLm).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the SLm material and unmeasurably low porosity in the SpS *** main aim of the study was the thorough microstructure characterisation and interrelation between the microstructure and the functional properties,such as mechanical strength,deformability,and corrosion *** materials showed comparable strength of∼110 mpa in tension and compression and relatively good deformability of∼9%and∼21%for the SLm and SpS materials,*** corrosion resistance of the SpS material in 0.1 m NaCl solution was superior to the SLm one and comparable to the conventional extruded *** digital image correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative effect on the functional properties of the SLm *** the other hand,one of the primary outcomes of this study is that the SpS consolidation method is very effective in the preparation of the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might find practical applications.

关键词： magnesium Yttrium powder metallurgy microstructure mechanical strength Corrosion resistance

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Impact of device resistances in the performance of graphene‑based terahertz photodetectors

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Frontiers of Optoelectronics 2024年第2期17卷 87-97页

作者： O.Castelló Sofía m.López Baptista K.Watanabe T.Taniguchi E.Diez J.E.Velázquez-pérez Y.m.meziani J.m.Caridad J.A.Delgado-Notario Department of Applied physics University of Salamanca37008 SalamancaSpain Unidad de Excelencia en Luz y materia Estructurada(LUmES) University of Salamanca37008 SalamancaSpain Research Center for Electronic and Optical materials National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Research Center for materials Nanoarchitectonics National Institute for Materials Science1-1 NamikiTsukuba 305-0044Japan Nanotechnology Group USAL-NanolabUniversity of Salamanca37008 SalamancaSpain

In recent years,graphene field-effect-transistors(GFETs)have demonstrated an outstanding potential for terahertz(THz)photodetection due to their fast response and *** features are essential to enable emerging THz applications,including 6G wireless communications,quantum information,bioimaging and ***,the overall performance of these photodetectors may be utterly compromised by the impact of internal resistances presented in the device,so-called access or parasitic *** this work,we provide a detailed study of the influence of internal device resistances in the photoresponse of high-mobility dual-gate GFET *** dual-gate architectures allow us to fine tune(decrease)the internal resistance of the device by an order of magnitude and consequently demonstrate an improved responsivity and noise-equivalent-power values of the photodetector,*** results can be well understood by a series resistance model,as shown by the excellent agreement found between the experimental data and theoretical *** findings are therefore relevant to understand and improve the overall performance of existing high-mobility graphene photodetectors.

关键词： Graphene THz photodetector Field-effect transistor plasmonic

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Characterization of bright betatron radiation generated by direct laser acceleration of electrons in plasma of near critical density

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matter and Radiation at Extremes 2024年第2期9卷 26-35页

作者： J.Cikhardt m.Gyrdymov S.Zähter p.Tavana m.m.Günther N.Bukharskii N.Borisenko J.Jacoby X.F.Shen A.pukhov N.E.Andreev O.N.Rosmej Faculty of Electrical Engineering Czech Technical University in Prague16627 Prague 6Czech Republic Goethe University FrankfurtMax-von-Laue-Straße 160438 Frankfurt am MainGermany GSI Helmholtzzentrum für Schwerionenforschung GmbH Planckstraße 164291 DarmstadtGermany Focused Energy GmbH Im Tiefen See 4564293 DarmstadtGermany National Research Nuclear University mEphI Kashirskoe shosse 31115409 MoscowRussian Federation Lebedev physical Institute RAS Leninskiy Prospekt 53119991 MoscowRussian Federation Heinrich-Heine-University Düsseldorf Universitätsstrasse 1DüsseldorfGermany Joint Institute for High Temperatures RASIzhorskaya st.13Bldg.2125412 MoscowRussian Federation moscow Institute of physics and Technology Institutskiy Pereulok 9141700 DolgoprudnyRussia

Directed x-rays produced in the interaction of sub-picosecond laser pulses of moderate relativistic intensity with plasma of near-critical density are investigated. Synchrotron-like (betatron) radiation occurs in the process of direct laser acceleration (DLA) of electrons in a relativisticlaser channel when the electrons undergo transverse betatron oscillations in self-generated quasi-static electric and magnetic fields. In anexperiment at the pHELIX laser system, high-current directed beams of DLA electrons with a mean energy ten times higher than the ponderomotive potential and maximum energy up to 100 meV were measured at 10^(19) W/cm^(2)laser intensity. The spectrum of directed x-raysin the range of 5–60 keV was evaluated using two sets of Ross filters placed at 0°and 10°to the laser pulse propagation axis. The differential x-ray absorption method allowed for absolute measurements of the angular-dependent photon fluence. We report 10^(13) photons/sr withenergies >5 keV measured at 0°to the laser axis and a brilliance of 10^(21) photons s^(−1) mm^(−2) mrad−2(0.1%BW)−1. The angular distributionof the emission has an FWHm of 14°–16°. Thanks to the ultra-high photon fluence, point-like radiation source, and ultra-short emissiontime, DLA-based keV backlighters are promising for various applications in high-energy-density research with kilojoule petawatt-class laserfacilities.

关键词： laser acceleration critical

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CD8+T cell metabolic flexibility elicited by CD28-ARS2 axisdriven alternative splicing of pKm supports antitumor immunity

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Cellular & molecular Immunology 2024年第3期21卷 260-274页

作者： G.Aaron Holling Colin A.Chavel Anand p.Sharda mackenzie m.Lieberman Caitlin m.James Shivana m.Lightman Jason H.Tong Guanxi Qiao Tiffany R.Emmons Thejaswini Giridharan Shengqi Hou Andrew m.Intlekofer Richard m.Higashi Teresa W.m.Fan Andrew N.Lane Kevin H.Eng Brahm H.Segal Elizabeth A.Repasky Kelvin p.Lee Scott H.Olejniczak Department of Immunology Roswell Park Comprehensive Cancer CenterBuffaloNY 14263USA Department of medicine Roswell Park Comprehensive Cancer CenterBuffaloNY 14263USA Human Oncology and pathogenesis program Memorial Sloan Kettering Cancer CenterNew YorkNY 10065USA Center for Environmental Systems Biochemistry Department of Toxicology and Cancer Biology and Markey Cancer CenterLexingtonKY 40536USA Department of Cancer Genetics and Genomics Roswell Park Comprehensive Cancer CenterBuffaloNY 14263USA present address:University of Colorado Boulder BoulderCO 80309USA present address:Dana Farber Cancer Institute BostonMA 02215USA present address:massachusetts Institute of Technology BostonMA 02139USA present address:melvin and Bren Simon Comprehensive Cancer Center Indiana University School of MedicineIndianapolisIN 46202USA

metabolic flexibility has emerged as a critical determinant of CD8+T-cell antitumor activity,yet the mechanisms driving the metabolic flexibility of T cells have not been *** this study,we investigated the influence of the nuclear cap-binding complex(CBC)adaptor protein ARS2 on mature T *** doing so,we discovered a novel signaling axis that endows activated CD8+T cells with flexibility of glucose ***2 upregulation driven by CD28 signaling reinforced splicing factor recruitment to pre-mRNAs and affected approximately one-third of T-cell activation-induced alternative splicing *** these effects,the CD28-ARS2 axis suppressed the expression of the m1 isoform of pyruvate kinase in favor of pKm2,a key determinant of CD8+T-cell glucose utilization,interferon gamma production,and antitumor effector ***,pKm alternative splicing occurred independently of CD28-driven pI3K pathway activation,revealing a novel means by which costimulation reprograms glucose metabolism in CD8+T cells.

关键词： Immunometabolism mRNA splicing CD8 T cells ARS2 pKm2

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Impact of COVID-19-related lifestyle changes on diabetic macular edema

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 97-106页

作者： Bryce p.Johnson Yu-Guang He Zachary m.Robertson Angeline Wang Rafael L.Ufret-Vincenty Department of Ophthalmology UT Southwestern Medical CenterDallasTexas 75390-9057USA

AIm:To assess diabetic macular edema(DmE)progression during the early phases of the COVID-19 pandemic,when severe societal restrictions raised the concern of possible deterioration of health in patients with systemic conditions,particularly those requiring frequent office ***:This is a multicenter retrospective chart review of 370 patients(724 eyes)with an established diagnosis of DmE seen on 3 separate visits between January 2019 and July *** 1 was January 2019 to February 2020(considered pre-COVID-19),period 2 was march 2020 to December 2020(considered the height of the pandemic;highest level of pandemic-related clinical and societal regulations)and period 3 was January 2021 to July 2021(re-adjustment to the new“pandemic norms”).main outcome measures included visual acuity,body mass index(BmI),blood pressure(Bp),hemoglobin A1c(HbA1c),macular thickness,patient adherence to scheduled ophthalmology visits,and DmE treatment(s)received at each *** facilitate measurement of macular thickness,each macula was divided into 9 Early Treatment Diabetic Retinopathy Study(ETDRS)-defined macular sectors as measured by OCT ***:There was no change of BmI,systolic Bp,and diastolic Bp between any of the time ***1c showed a very small increase from period 1(7.6%)to period 2(7.8%,p=0.015)and decreased back to 7.6%at period 3(p=0.12).macular thickness decreased for 100%of macular *** central macular thickness decreased across all 3 periods from 329.5 to 316.6μm(p=0.0045).After analysis of multiple variables including HbA1c,BmI,adherence to scheduled appointments,different clinic centers,and treatment interventions,there was no easily identifiable subgroup of patients that experienced the increase in ***:DmE doesn’t worsen during the COVID-19 pandemic,instead sustaining a very small but statistically significant *** identifying a mechanism behind our findings is beyond the scope of this study,potential explanat

关键词： COVID-19 diabetic macular edema diabetic retinopathy optical coherence tomography

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In vivo and in vitro study of resorbable magnesium wires for medical implants:mg purity,surface quality,Zn alloying and polymer coating

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Journal of magnesium and Alloys 2024年第6期12卷 2472-2488页

作者： K.Tesar J.Luňácková m.Jex m.Žaloudková R.Vrbová m.Bartoš p.Klein L.Vištejnová J.Dušková E.Filová Z.Sucharda m.Steinerová S.Habr K.Balík A.Singh Department of materials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic Institute of physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic Institute of Dental medicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Department of physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Department of Composites and Carbon materials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic Institute of Anatomy First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biomedical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Department of pathological physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Department of Histology and Embryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Institute of pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Department of Biomaterials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for Structural materials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

magnesium is an excellent material in terms of biocompatibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation limit the potential of mg-based *** low-alloyed mg-Zn wires can strongly reduce problems with large H_(2)bubbles and improve the mechanical properties considerably while maintaining excellent long-term *** pickling and a polymer coating can be effectively used to lower the rate of in vivo *** this work,microstructural,mechanical,and in vitro characterization of 250μm and 300μm extruded wires made from ultra-pure mg,commercially pure mg,mg-0.15Zn,mg-0.4Zn and mg-1Zn was ***,mg-0.4Zn wires together with a variant coated with a copolymer of L-lactide andε-caprolactone were tested in vivo on artificially damaged Wistar rat *** on the observed mg-induced osteogenesis,polymer-coated mg wires with a small addition of Zn are a perspective material for bone-support applications,such as cerclage and fixation wires.

关键词： magnesium Resorbable mg wire mg-Zn implant degradation Biocompatibility study Zn grain boundary segregation

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Overview of the Association Between Non-Alcoholic Fatty Liver Disease and Hypertension

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Cardiology Discovery 2024年第1期4卷 30-37页

作者： Niki S.Kakouril Costas G.Thomopoulos Eirini p.Siafi Angeliki E.Valatsoul Kyriakos S.Dimitriadis Iliana p.mani Sotirios p.patsilinakos Dimitrios m.Tousoulis Konstantinos p.Tsioufis First Department of Cardiology Medical SchoolNational and Kapodistrian University of AthensHippokration HospitalAthens 11527Greece Department of Cardiology Elena Venizelou HospitalAthens 11521Greece Department of Cardiology General Hospital Agia OlgaAthens 14233Greece

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and its prevalence is rising. NAFLD is closely associated with metabolic syndrome, with both conditions sharing common clinical characteristics such as obesity, insulin resistance, type 2 diabetes mellitus, hypertension, and hypertriglyceridemia. Several observational studies have evaluated the relationship between NAFLD and hypertension, with the overall evidence suggesting a bidirectional relationship. It is hypothesized that activation of the sympathetic nervous and renin-angiotensin systems, observed in NAFLD with or without insulin resistance promotes the development of hypertension. In patients with hypertension, activation of these systems can lead to hepatic fibrosis and progressive inflammation through increased oxidative stress and activation of hepatic stellate cells and Kupffer cells. The present review examines the pathophysiologic and clinical evidence supporting the bidirectional association between NAFLD and hypertension.

关键词： Hypertension Non-alcoholic fatty liver disease Insulin resistance Sympathetic nervous system metabolic syndrome

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Frequency-dependent viscoelasticity effects on the wave attenuation performance of multi-layered periodic foundations

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 407-424页

作者： m.SAFI m.VAKILIFARD m.J.mAHmOODI Faculty of Civil Water&Environmental EngineeringShahid Beheshti UniversityTehran ***Iran Faculty of mechanical and Energy Engineering Shahid Beheshti UniversityTehran ***Iran

In this paper,layered periodic foundations(LpFs)are numerically examined for their responses to longitudinal and transverse modes in the time and frequency *** different unit-cells,i.e.,2-layer,4-layer,and 6-layer unit-cells,comprising concrete/rubber,concrete/rubber/steel/rubber,and concrete/rubber/steel/rubber/lead/rubber materials,respectively,are taken into ***,the viscoelasticity behavior of the rubber is modeled with two factors,i.e.,a frequency-independent(FI)loss factor and a linear frequency-dependent(FD)loss *** the extraction of the complex dispersion curves and the identification of the band gaps(BGs),the simulations of wave transmission in the time and frequency domains are performed using the COmSOL *** parametric studies evaluate the effects of the rubber viscoelasticity models on the dispersion curves and the wave transmission for the longitudinal and transverse *** results show that considering the rubber viscoelasticity enhances the wave attenuation ***,the transverse-mode damping is more sensitive to the viscoelasticity model than its longitudinal *** 6-layer unit-cell LpF exhibits the lowest BG,ranging from 4.8 Hz to 6.5 Hz.

关键词： layered metamaterial periodic foundation complex dispersion curve wave transmission diagram

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In-situ construction of grass-like hybrid architecture responsible for extraordinary corrosion performance: Experimental and theoretical approach

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Nano materials Science 2024年第1期6卷 44-59页

作者： T.Suhartono F.Hazmatulhaq Y.Sheng A.Chaouiki m.p.Kamil Y.G.Ko materials Electrochemistry Group School of Materials Science and EngineeringYeungnam UniversityGyeongsan38541Republic of Korea Research Center for Advanced materials National Research and Innovation Agency(BRIN)South TangerangBanten15314Indonesia

Despite the engineering potential by the co-existence of inorganic and organic substances to protect vulnerable metallic materials from corrosive environments,both their interaction and in-situ formation mechanism to induce the nature-inspired composite remained less *** present work used three distinctive mercaptobenzazole(mB)compounds working as corrosion inhibitors,such as 2-mercaptobenzoxazole(mBO),2-mercaptobenzothiazole(mBT),and 2-mercaptobenzimidazole(mBI)in a bid to understand how the geometrical structure arising from O,S,and N atoms affected the interaction toward inorganic *** compounds that were used here to control the corrosion kinetics would be interacted readily with the pre-existing mgO layer fabricated by plasma *** phenomenon triggered the nucleation of the root network since mB compounds were seen to be adsorbed actively on the defective surface through the active sites in mB ***,the molecule with twin donor atoms adjacent to the mercapto-sites affected the facile growth of the grass-like structures with‘uniform’distribution via molecular self-assembly,which showed better corrosion performance than those with having dissimilar donor atoms with the inhibition efficiency(η)of 97%*** formation mechanism underlying nucleation and growth behavior of mB molecule was discussed concerning the theoretical calculation of density functional theory.

关键词： Nature-inspired composite Organic-inorganic interaction Corrosion inhibitor Density functional theory Electrochemistry

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